Improved slate-polishing machine



@anni @like STINSON 1HAGAMAN, 0F WEISSPORT, PENNSYLVANIA.

Letters .Patent No. 94,309, dated August'l, 1869.-

IIMPROVED SLATE-POLISHING- MACHINE.

The Schedule referred to in these Letters Patent and making part of the same.

To all whom 'it may concern;

Be it knownthat I, S'rrusou HAGAMAN, of Weissport, Carbon county, Pennsylvania, have invented new and-improvedSlate-Polishing Machine; and I d` hereby declare'that the following is a full, clear, and exact description thereof, which will enable others skilled in the art to makeand use the same,.refer ence being had to theI accompanying drawings, forming part of this specification, in which- Figure 1 represents a plan or top view of my irnproved slate-polishing machine.

Figure 2 isa side elevation of thesame.

Figure 3 is a horizontal,sectionalview of the same, the plane of section being indicated by the line xx, fig.2.

Similar letters of reference indicate corresponding parts.l

. This invention relates to amaehine for grinding school-slams, in which gr-ndstones of different grades of grit are arranged in sucha manner that the slates can. be ground to the required thickness, and then polished, and their faces smoothened underthe various grindstones, without being taken out of the mould in which they are held.

shafts.

The invention consists, second, in arranging two or more upright shafts at equal distances from the aforesaid central shaft, but beyond the slate-bearing shafts, and in mounting on each, disks or wheels, made or cousisting of suitable grinding-material.'

' These grindstone's, as I will hereafter term them, although they may be emexy, hone, or otherartiicial or natural wheels, are arranged above the slates, and

'are revolved in an opposite direction to that in which the central shaft moves.

The invention consists, third, in the manner of hanging the aforesaid slate-carrying lshafts in the disks that are secured to the central shaft.

Theshafts pass loosely through boxes arranged for them in the said disks, and the lower end ef each of them rests upon a spring, of which one endis secured to the under side of the lower disk, .while its other end carries a friction-roller.

The latter moves (as the central shaft revolves j upon a stationary annular track, and the spring serves to gently press the slate against the grindstone.

lclearly shown in fig. 3.

By means'of adjustable sleeves, arranged below one of the disks on each of the slate-carrying shafts, the latter can be set, so that the slate can only be ground to a certain required thickness.

A. represents a rectangular or other frame, made of; wood, or any other suitable material of sufficient strength to support and hold. the other working-parts of this machine.

B is an upright shaft, having its bearings in the frame A, and received v by means of gear-wheels a, which transmit slow motion to it from a driving-shaft, that is not shown in the drawings.

O C are two or more disks, mounted on the shaft B, so as to revolve with thesame. l

D D are ten (more or less) vertical shafts, which are tted through the disks C, so as to slide loosely therein.

E is an annular track oi' plate, arranged stationary F F are ten (more or less) springs, 'which are secured to the under side of the lower disk O, and which are providedat their free ends with friction-rollers b, that rest upon the trackE. The lower ends of the shafts D rest upon these springs, as is clearly shown in iig. 2.

On the upper end 'of ea'ch shaft D is mounted a small disk, G, in the upper surface of whioha suitable recess is provided, for holding the "slate to be ground.

On" each shaft D is mounted asmall pinion', c, all of which pinions mesh into a stationary toothed segment, H, which is provided with internal gear, as

Thus, as the central shaft B is revolved in the li-- rection of the arrow l, in fig. l, the shafts D and their appendages will be carried around the vaxis of the shaftB, but will also revolve around their own axis, in the direction of the arrow 2 in flg. 1.

I I are two or more upright shafts, arranged in the frame A, at equal distances from thc shaft B, and outside of the disks C. On the upper ends of these shafts are mounted the grinding wheels J, J1, and J2, which are of different grade of grit, the wheel J being the coarsest, and J2 the finest.

Shafts I are revolved by means of bolts d, or otherwise, inthe direction of the arrows 3, in fig. l, with greater velocity than the shaft B.

The slates are pressed by the springs F against the grinding-s1ufaces of the wheels J.

e e are sliding sleeves, arranged on the shafts d, below` one of the disks .0, and can be secured in any position by set-screws f.

g are nuts, whichare arranged around the shafts D, directly below the sleeves e, so that when thesetscrew is loosened, the said sleeve can be very accw rately adjusted up down, vby means of these nuts.

rIhereby the springs are prevented from pressing the slates too far against the grinding-wheels, and the thickness of the slates Acan be regulated with the greatest accuracy.

The grinding-wheels may, if desired, be adj us'tabie on their shafts I, in a similar manner, and for the same purpose.

The slates only revolvev around their own axis as l long as they are below the grinding-Wheels, as the segy ishing school-slates that the slates are revolved around the axes of the shafts on which they are held, and

around the axis of 'a central shaft, B, substantially as herein shown and described.

2. The annular track E, springs F, and frictionrollers b, when arranged in combination with the revolving disks C and shafts D, substantially as and for the purposes herein shown and described.

3. The stationary segment H, when provided with internal gear, in combination with the pinions c, on the shafts D, and with the central 'shaft B and disks C,

vsubstantially as and for the purpose herein shown and described. v

4. Thenuts g and sleeves e, when arranged on the and grinding-wheels J, all made and operating substantially'as herein shown and described.

` STINSON HAGAMAN.

Witnesses:

vWM. F. MGNAMl ARA ALEX. F. ROBERTS.

shafts D, in combination with the springs F, disks C, 

